Marginal Fit of Three Commonly Used Veneers for Smile Enhancement: An In Vitro Study

The objective of the present study was to evaluate the marginal fit of three most commonly used veneers in dentistry.

A maxillary central incisor was embedded in a self-cure acrylic resin block, with the crown and 2 mm of the root exposed to facilitate standardized tooth preparation. Following the preparation, 30 elastomeric impressions were made to produce master casts. These working dies were then randomly allocated to three experimental groups, each consisting of 15 samples. Group I comprised indirect composite veneers (ICV), fabricated using laboratory composite resin. Group II included pressable ceramic veneers (PCV), manufactured using heat-pressed lithium disilicate. Group III consisted of computer-aided designing (CAD)/computer-aided manufacturing (CAM) ceramic veneers, fabricated through digital milling of lithium disilicate blocks. All veneers were fabricated in accordance with the respective manufacturer's guidelines and were carefully repositioned on the prepared tooth to evaluate the marginal discrepancy using a stereomicroscope.

Three pre-designated points-mesio-labial, mid-labial, and disto-labial and mesio-palatal, mid-palatal, and disto-palatal on the labial and palatal margins-were measured. The values were recorded and analyzed with one-way ANOVA and Tukey's post-hoc test using SPSS software.

ICV showed more variation with mean discrepancy of 189.24 ± 25.17 µm at cervical margin and 79.01 ± 11.68 µm at palatal area. PCV showed less variation with mean discrepancy of 48.2 ± 8.35 µm and 40.58 ± 9.47 µm at cervical and palatal areas, respectively. CAD/CAM-fabricated ceramic veneers showed mean discrepancy of 94.24 ± 9.00 µm at cervical and 52.72 ± 16.33 µm at palatal areas.

Pressable ceramic veneers showed the best marginal fit at both cervical and palatal margins followed by CAD/CAM veneers. Indirect composite veneers showed poorest marginal fit. The marginal discrepancy values were within the clinically acceptable range for PCV and CAD/CAM ceramic veneers.

It is of paramount importance that the dentist should choose wisely the veneer material taking the marginal fit into account.